Because I often work with ardour, carla, hydrogen, etc...It would be nice to be able to run, save and close guitarix from non-session-manager.The default behaviour of the -f option is good for that, it loads the default config file if file doesn't exists and save it in the new file.This way, the default file would be loaded at start of a new NSM session, and little adjustements loaded at re-open of the NSM session.

Well, I've my doubts about NSM, but, we will accept patches as long jack session manager support don't to be removed. The best implementation for NSM support will be, if NSM support is de/selectable during configure. An implementation like this we will surely accept.